Date of Original Version
An investigation into the structure and composition of hydrogen flouride vapor is reported. Calculations are performed using a modified central force model potential developed by Klein and McDonald. Using a simulated annealing procedure, minimum energy structures for HF clusters are investigated ranging in size from n=2 to 7. Good agreement is found for the sturctural parameters obtained from the model potential and other theoretical and experimental information. The Monte Carlo method is used to determine the thermodynamic energy, entropy, and Gibbs free energy of the hydrogen flouride clusters at 1 atm pressure and 100 and 273 K. A minimum in the Gibbs free energy change is found at n-=4 implying that tetramers are very important in vapor.
C. Zhang, D.L. Freeman and J.D. Doll, “Monte Carlo Studies of Hydrogen Fluoride Clusters: Cluster Size Distributions in Hydrogen Fluoride Vapor,” J. Chem. Phys. 91, 2489 (1989).